The present invention relates to the control of arthropods such as termites and, in particular, to devices that lie on the ground and can be used to restrict and/or direct the movement of arthropods.
Termites are well known throughout most areas of the world as insects that attack and destroy wooden structures. Subterranean termites most often enter structures from the surrounding soil to feed on wood or other cellulosic material of the structure and its contents. Many methods for killing termites have been employed over the years. One such method involves applying a toxicant (i.e., a material that kills or repels termites) to the soil in the vicinity of a structure that is to be protected from termites. Not only is this type of treatment labor intensive and raises issues about soil contamination, but the application may not produce an adequate barrier to termite infestation.
Another approach to termite control involves the insertion of wooden stakes or some other suitable termite bait material into the soil around the periphery of the structure to be protected, monitoring the stakes for infestation, and then applying a toxicant to the soil only in those areas in which infestation is observed. This approach minimizes use of the toxicant, yet presents other problems. The bait stakes, for example, do not provide a continuous barrier around the structure, as they typically occupy limited area and, moreover, are separated from one another by a distance on the order of feet or even yards. Termite populations located in the soil can have difficulty locating the bait stakes in the first place, especially if the bait stakes are widely spaced and located on a predetermined interval irrespective of conditions around a structure conducive to termite attack, such as moist areas around a structure. Also, removal of the bait stakes can disrupt the system of passageways leading to the stake that termites may have constructed and, in turn, can disrupt the flow of termites to the stake upon stake re-insertion. These problems are said to be addressed by U.S. Pat. Nos. 5,573,760 and 5,555,672, both in the name of Thorne et al., which disclose insertion into the ground of a stationary housing that not only contains a removable bait cartridge but also possesses a plurality of extensions which are said to intercept or obstruct the path of termites in the vicinity of the housing.
Like "bare" bait stakes, however, the devices disclosed by Thorne, et al., are subterranean devices that typically are inserted completely into the soil so as to be flush with its surface. Accordingly, it often can be difficult to locate such structures after insertion for purposes of further monitoring.
Consequently, there is a need in the art for devices that are more easily located than subterranean bait/toxicant devices and/or for some means for locating such devices. Additionally, there is a need to arrest termites that may be near a subterranean device and to direct them to such a device.